Provides files to download data as it existed for this dataset on previous dates.

Statistics are most often revised for 1 of 2 reasons:

  1. For certain statistics initial estimates are released with the expectation that these may be revised and updated as further data becomes available.
  2. Revisions may also be made when methods or systems are changed.

These types of planned revisions should not be confused with errors in released statistics, which are genuine mistakes. Such mistakes occur rarely and, when they do happen, corrections are made in a timely manner, announced and clearly explained to users in line with the Code of Practice for Official Statistics (Principle 2, Practice 7).

Latest version

xlsx (77.8 kB)

Previous versions

Superseded files Reason for update Date superseded
xlsx (74.6 kB)
Correction See correction
Following this release, we identified a number of quality issues: - our grouping of 'classic' symptoms had excluded fever when it should have been included in that category - results from a small number of participants who had experienced a positive test followed by a negative test within the 35 day period of the analysis had been previously excluded from the analysis due to a coding error - estimates for March were based on data from 1 March to 20 March 2021 and should have used available data up to and including 22 March 2021 These corrections have resulted in a change to the estimated percentage of people reporting any symptoms from 47% to 49% and the estimated percentage of people reporting no symptoms has changed from 53% to 51%. The estimated percentage of people reporting 'classic' symptoms has also changed from 36% to 43% and there are additional changes to data for past time periods. These changes have not affected the main trends presented in this release. We are reviewing our quality assurance procedures and apologise for any inconvenience caused.
19 April 2021 07:33